Drawing of wires



Jan. 21 1936.

J. DE MULATIER DRAWING 0F WIRES:

I Filed June 29, 1954 'jiuvENroQ: a 4L Mm Patented Jan. 21, 1936 UNITEDSTATES PATENT OFFICE 5 Claims.

My invention relates to the drawing of wires.

A good drawing requires a low temperature of the drawing cone of the dieand a high countertension within the die. The temperature of the drawingcone is kept as low as possible by the provision of cooling means withinthe die holder, but such means absorb heat from the die only byconduction through the mass of the die holder. Since heat is generatedon the extremely small surface of the drawing cone, the latter is liableto become overheated notwithstanding such cooling means.

It is possible to lower the temperature of the drawing cone by reducingthe elongation of the wire Within the die. But this reduces thecountertension near the outlet of the drawing cone; the pressure of themetal of the wire against the inner surface of the die becomes too highand the cone wears out too rapidly. Also the number of drawingoperations for a given elongation becomes too great. I

According to my invention several dies are disposed in succession witheach other,,preferably co-axially in the same die-holder and the wire ispassed through them at the same time on its way to the drawing spool.

In the annexed drawing:

Fig. 1 is a longitudinal section of a die holder according to myinvention.

Fig. 2 is an end view thereof with partial section through line IIII ofFig. 1.

Fig. 3 is a perspective view of the hollow stay.

Fig. 4 is a perspective view of the split conical member.

The die holder comprises a cylindrical body I having a conicalcentralbore into which is fitted a split conical member 2 held by an annularcover 3 which is screwed into a threaded cylindrical recess 4 of body I.The latter has two circular grooves 5 on its outer surface. A tube 6 isfitted over the grooved portion of body I so as to close the grooveswhich thus form canals for the cooling fluid. Two hollow studs I areadapted for the inlet and the outlet of said fluid. The grooves areconnected with each other by longitudinal passages 8, such passagesbeing preferably provided in the portion opposite to the studs 1.

A transverse hole 9 is also provided through body I and tube 6, suchhole being used for the admission of lubricant to the dies.

The tightness of the joints is preferably ensured by soldering.

The split conical member 2, Fig. 4, has a cylindrical internal bore witha. restricted outlet as shown at I0, Fig. 1. It' encloses the first-stepdie I I and the finishing die I2 separated from each other .by acylindrical hollow stay,I3, Fig. 3, having opposed grooves I4 arrangedto permit of admitting lubricant to the wire between the 5 'dies II andI2. The split conical member 2 is it self transversely pierced, as shownat I5, to afford a communication between hole 9 and the grooves I4 ofstay I3.

An annular stay I6 is arranged between the 0 first-step die II and theface of cover 3.

The wire is drawn from left to right. It passes through the first-stepdie I I and thence through the finishing die I2, lubricant being ifneeded admitted at will by means of hole 9. 15

Since the contraction of the wire is small for each die, the amount ofheat generated is reduced and the latter easily flows through the metalof the dies, of member 2 and of body I, without the temperature of thedrawing cones becoming unduly high. The conditions of working are goodfor the finishing die I2 since the wire which passes through the same isalready tensioned owing to the drawing through the first step die II.The bore of the finishing die is thus well preserved from wear and thesize of the wire remains unaltered during the drawing operation. In facthigh drawing speeds are attainable without risk of wire breakage andwithout an abnormal wear of the dies.

A further advantage of my invention is that the dies I I and I2 areradially compressed by the split conical member. This compressionbalances the radial action resulting from the drawing of the wire andthe strain on the metal of the external part of the die is suppressed.The radial action of the wire on the die being also reduced owing to thedecrease of the elongation, it becomes possible to use smaller .dies.The cost of the dies is therefore greatly lowered. 40

I claim:

1. A wire drawing device comprising in combination a cylindricaldie-holder having circular grooves on its outer periphery; a tubetightly fitting on said grooved portion; a cooling fluid inlet incommunication with one of said grooves; -a cooling fluid outlet incommunication with another one of said grooves; and passages betweensaid grooves to ensure circulation of the cooling fluid.

2. Awire drawing device comprising in combination adie holder having aconical axial bore with a threaded cylindrical recess of larger diameterat the entrance thereof and a transverse hole;

a split cone fitting into said conical axial bore, said split conehaving a cylindrical axial bore with restricted outlet at the tip of thecone and a transverse passage able to register with said transversehole; two cylindrical drawing dies arranged in said cylindrical axialbore respectively n one and the other side of said transverse pas- .age;a hollow stay in said cylindrical bore, said stay having groovesaffording a radial passage; an annular screw axially screwed into saidthreaded recess to axially press said split cone into said conical axialbore to radially compress said drawing dies; and a tubular stayinterposed between said annular screw and the adjacent one of saiddrawing dies.

3. A high-speed drawing device for plain cylindrical wires comprising incombination a dieholder; a plurality of drawing dies of decreasingdiameter co-axially arranged within said dieholder; means to radiallycompress said drawing dies within said die-holder; and means to axiallyretain said drawing dies in proper relation within said die-holder, saiddie-holder and said firstnamed and second-named means having holesprovided between each two successive drawing dies to afford a passagefor circulating lubricant.

4. A high-speed drawing device for plain cylindrical wires comprising incombination a dieholder having a conical axial bore; a split conefitting into said conical axial bore, said split cone having acylindrical axial bore with restricted outlet at the tip of the cone; aplurality of cylindrical drawing dies arranged in said cylindrical axialbore in such relation that their diameters decrease from the inlet ofsaid last-named bore down to its restricted outlet; a hollow stay insaid cylindrical bore between each two successive drawing dies; andmeans to axially press said split cone into said conical axial bore toradially compress said drawing dies.

5. A high-speed drawing device for plain cylindrical wires comprisingin, combination a dieholder having a conical axial bore with a threadedcylindrical recess of larger diameter at the entrance thereof; a splitcone fitting into said conical axial bore, said split cone having acylindrical axial bore with restricted outlet at the tip of the cone; a.plurality of cylindrical drawing dies 'arranged in said cylindricalaxial bore in such relation that their diameters decrease from the inletof said last-named bore down to its restricted outlet; a hollow stay insaid cylindrical bore between each two successive drawing dies; anannular screw axially screwed into said threaded recess to axially presssaid split cone into said conical axial bore to radially compress saiddrawing dies; and a tubular stay interposed between said annular screwand the adjacent one of said drawing dies.

JEAN nr: MULA'IIER.

